Web-picture-message transmission



April 14,1925. 1,533,422 C. F. JENK|N$ WEB PICTURE MESSAGE TRANSMISSION Filed Feb. 16. 1924 and Patented Apr. 14', 1925.

CHARLES FRANCIS JENKINS, OF WASHINGTON, DISTRICT OF COLUMBIA.

WEB-PICTURE-MESSAGE TRANSMISSION.

Application filed February lG, 192s. Serial No. 693,226.

To all whom it may concern:

vBe it known that I, CHARLES FRANCIS JENKINS, citizen of the United States, residing at lWashington, District of Columbia, have invented certain new and useful Improvements in lVeb-Picture-Messagc Transmissions, of which the following is a specification.

This invention relates to apparatus for the transmission of photos, maps, and photo-messages by radio, and has for its principal object a construction permitting continuous operation at high speed over an extended period. Another object is to secure the highest degree of efliciency possible of the incoming radio signals,.with as nearly perfect modulation as can be attained.

So far as applicant is aware no means have before been devised whereby a continuous web of typewritten matter can be sent or received by photographic process in' characters small enough to make legible writing om an ordinary typewriter, and sent fas enough to be commerclally satisfactory.

The reason for this is that no light source has been found which is both small enough powerful enough for the purpose, that is, small enough for minute figures and at the same time intense enough to permit high speed.

Applicant accomplishes this by employin};- a light of sufficient intensity, and then interposes a mask between the light and the photographic light-sensitive surface with an aperture therein smaller than the finest picture detail.

Those skilled in the art to which this invention pertains will readily understand that the light-sensitive surface may be shielded or masked in many different ways,

limiting the. light to that which passes through the miniature aperture, and with-- out departing from the spirit of applicants invention, which in this respect consists in longitudinally passing a photographic film under a minute aperture which is itself moving laterally of the film.

It will also be understood that the film may have photos, sketches, maps or messages thereon, or only exposures of such which are yet to be chemically developed, and to cover these several conditions apposed to the light for the longest time as plicant will describe the strip as a picture surface, minute successive areas of which it is desired to uncover by means of a. small aperture in a. mask in cont-act therewith, all of which is hereinafter described and further pointed out in the claims.

In the illustrations Fig. 1 is a schematic drawing of the invention, and Fig. 2 acrosssect-ion detail thereof on the line X Y: in both of which A is a. picture film; B a. roller from which; it is pulled, and wound onto a roller C, connected through gear D, worm E. and gears F and G to box H, which contains lamps T and J. Through the box or casing wall, and in alignment with the filaments of the lamps, are square apertures K and K. A. brush-like device L is provided to hold the picture surface in intimate contact with the apertured' mask.

The lamps are in circuit with a battery N and the secondary of a transformer Q, the primary of which is in circuit with the plate ofthe last amplifier tube of a receiving set R.

The battery N is so chosen that the filaments of the lampsare brought to a red glow, however without photographic effect at the speed of movement of the lamp aperture over the light-sensitive surface.

Any prime mover may be belted to the pulley M and motion given to the device. When this is done the picture surface is drawn along by the rotation of roller C, at the same time that the apertured mask H is rotated at approximately right angles to the movement of the picture film. The gearing ratio is such that for each half revolution of the mask, or lamp casing, the film is drawn along a distance about equal to the diameter of the aperture, if the aperture is round, or if square then equal to the side. A very decided improvement in portraits is effected by having the aperture square, though this is not so important in message work. As the diameter of a circular aperture is the longest line that can be drawn across such an opening, it is obvious that along this line the film is e12 ll 18 film moves under the aperture, the lateral edges of the aperture permitting only a short exposure. Therefore the picture shows lines. Whereas if the aperture is square and the movement is parallel to one side it is comparable to a painters brush, for it exposes the whole width of the line uniformly, and the photograph is without perceptible lines.

The operation of the device is as follows- Assuming the instrument to be put in motion, and that the strength of the incoming radio signals represent successive values of the light in the various parts of the picture at the sending station, the high lights, the half-tones and the shadows, then the light from the lamp will fluctuate accordingly, that is, the lamp will burn brightly for strong signals, less bright for weaker signals and dimly. for very weak signals representing the shadows of thepicture at the sending station. The exposure of the light-sensitive film under the aperture will vary, therefore, as the aperture travels across the film. And as the film also is in motion, the exposures under the successive lines made by the moving aperture will build up areas of density representing high lights, less dense areas for half-tones, and thin areas for the blacks of the picture being received; and paper prints from this negative, after development, will be duplicates of the original picture at the sending station.

Obviously modifications of the invention herein disclosed are possible, but applicant is not aware that others have heretofore discovered or employed the essentials herein set forth; or the combination of them to produce this new and important advance in the art; i. e., (1) a square-apertured mask: (2) in contact with a picture surface; upon which impinges (3) a modulating light having an initial heat to most efiectually employ the incoming radio signals.

What I claim, therefore, is-

1. In apparatus of the class described, the combination of a moving picturesurface, a moving light-enclosing casing in contact with said picture surface, a minute aperture in said casing at the point where it contacts with said surface, and means for yieldingly holding the casing and said picture surface in intimate contact.

2. In apparatus of the class described, the'coinbination of a picture surface, a light-enclosing casing in contact with said picture surface, a minute aperture in said light-casing at the point where it contacts with the plcture surface, means for permitting a predetermined movement between the casing and said surface in crossed directions, and means for holding the casing and said surface in intimate contact.

3. In apparatus of the class described, the combination of a picture surface, a lightenclosing casing in contact with said surface, a minute aperture in said light casing at the point where it contacts with said picture surface, and means for permitting a predetermined movement between the light casing and the picture surface in crossed relation.

4. In apparatus of the class described, the combination of a longitudinally-moving web-like picture surface, a laterally-moving light-mask in intimate contact with the web like surface, and having an aperture therein at the point of contact, and means for maintaining a predetermined crossed direction relation between the two moving parts.

5. In apparatus of the class described, the combination of a longitudinally-moving web-like picture surface, a laterally-moving light-mask in intimate contact with the: web-like surface, and having an aperture therein at the point of contact, and means for maintaining a predetermined crossed direction relation between the two moving parts, and means for yieldingly holding the mask and web-surface in intimate contact.

6. In apparatus of the classdescribed, the combination of a photographically lightsensitive web-like surface, a source of light, means for directing said light upon, and moving same over said sensitive surface in a transverse direction, and means for modulating said light intensity.

7. In apparatus of the class described, the combination of a photographically lightsensitive surface, an incandescent filament light-source, means for directing said light upon and moving same over said sensitive surface, means for initially heating said filament to a feeble glow, and means for modulating the intensity of said light source above the initial glow.

8., In apparatus of the class described, the combination of a photographically lightsensitive surface, a source of light, a mask between said light and said sensitive surface, the mask being in contact with the said surface, and having a minute square aperture therein where the mask contacts with the said surface, means for moving both the surface and the apertured mask, the mask moving laterally of the movement of the surface.

In testimony whereof I have affixed my signature,

CHARLES FRANCIS JENKINS. 

